Combine the WET core CSS in the theme CSS

Partially implements #6809

site/includes/headresources.hbs

@@ -1,12 +1,11 @@
 <!--[if gte IE 9 | !IE ]><!-->
 <link href="{{assets}}/assets/favicon.ico" rel="icon" type="image/x-icon" />
-<link rel="stylesheet" href="{{assets}}/css/wet-boew{{environment.suffix}}.css" />
-<!--<![endif]-->
 <link rel="stylesheet" href="{{assets}}/css/theme{{environment.suffix}}.css" />
+<!--<![endif]-->
 {{#if page.css}}{{#each page.css}}<link rel="stylesheet" href="{{this}}{{../environment.suffix}}.css" />{{/each}}{{/if}}
 <!--[if lt IE 9]>
 <link href="{{assets}}/assets/favicon.ico" rel="shortcut icon" />
-<link rel="stylesheet" href="{{assets}}/css/ie8-wet-boew{{environment.suffix}}.css" />
+<link rel="stylesheet" href="{{assets}}/css/ie8-theme{{environment.suffix}}.css" />
 <script src="http://ajax.googleapis.com/ajax/libs/jquery/{{environment.jqueryOldIEVersion}}/jquery{{environment.suffix}}.js"></script>
 <script src="{{assets}}/js/ie8-wet-boew{{environment.suffix}}.js"></script>
 <![endif]-->

theme/theme.scss

@@ -13,6 +13,13 @@
 @import "variables";
 @import "defaults";
 
+/* WET Core */
+/*
+ * GLYPHICONS Halflings for Twitter Bootstrap by GLYPHICONS.com | Licensed under http://www.apache.org/licenses/LICENSE-2.0
+ */
+@import "../src/base/bootstrap";
+@import "../src/base/wet-boew";
+
 @import "banner/base";
 @import "breadcrumb/base";
 @import "footer/base";

theme/wet-boew.scss

@@ -2,9 +2,4 @@
  * Web Experience Toolkit (WET) / Boîte à outils de l'expérience Web (BOEW)
  * wet-boew.github.io/wet-boew/License-en.html / wet-boew.github.io/wet-boew/Licence-fr.html
  */
-/*
- * GLYPHICONS Halflings for Twitter Bootstrap by GLYPHICONS.com | Licensed under http://www.apache.org/licenses/LICENSE-2.0
- */
-@import "variables";
-@import "../src/base/bootstrap";
-@import "../src/base/wet-boew";
+/* Deprecated */